:root{font-family:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:#18313c;background:#f1f5f7;font-synthesis:none}*{box-sizing:border-box}body{margin:0}header{max-width:1280px;margin:auto;padding:26px 42px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #d7e1e6}a{color:inherit}.brand{display:flex;align-items:center;gap:12px;text-decoration:none;font-weight:750;font-size:30px}.brand-icon{color:#007a93;font-size:42px;line-height:1}.brand-sub{font-size:11px;letter-spacing:2px;font-weight:600;margin-left:16px;color:#647a83}.standard{font-size:13px;color:#58717d}.standard span{padding:0 10px;color:#97aeb8}main{max-width:1280px;margin:auto;padding:38px 42px 20px}.heading{display:flex;justify-content:space-between;align-items:center;margin-bottom:32px}.eyebrow{font-size:12px;letter-spacing:2px;font-weight:700;color:#00758b;margin:0 0 13px}h1{font-size:42px;font-weight:550;letter-spacing:-1.4px;line-height:1.13;margin:0}.intro{font-size:16px;line-height:1.65;color:#647985;border-left:2px solid #b9d4dc;padding-left:24px;margin-right:26px}.workspace{display:grid;grid-template-columns:360px 1fr;gap:20px}.panel{background:white;border:1px solid #dce5e9;border-radius:16px;padding:26px}.inputs{grid-row:span 2}.section-title{display:flex;align-items:center;gap:12px;margin-bottom:26px}h2{font-size:18px;font-weight:600;margin:0;letter-spacing:-.3px}.number{font-size:12px;color:#69828c;border:1px solid #cbdce2;border-radius:50%;width:27px;height:27px;display:grid;place-items:center;flex-shrink:0}label{display:block;font-size:14px;font-weight:550;margin-bottom:9px}select,input,button{font:inherit}select{max-width:100%;cursor:pointer}#pair{width:100%;padding:13px 9px;background:#f4f8fa;border:1px solid #d3e0e5;border-radius:8px;font-size:14px;color:#1b4656}.field{margin-top:25px}.input-row{display:flex;border:1px solid #c4d6de;border-radius:9px;overflow:hidden;background:white}.input-row:focus-within{outline:2px solid #007e99;outline-offset:2px}input{min-width:0;width:100%;border:0;outline:none;padding:14px;font-size:25px;font-weight:500;font-variant-numeric:tabular-nums;color:#183844}.input-row select{max-width:135px;border:0;background:#f4f8fa;color:#526e7b;padding:8px;font-size:14px}.hint{color:#647c88;line-height:1.5;font-size:13px;margin:16px 0}button{cursor:pointer}.calculate{display:flex;align-items:center;justify-content:space-between;width:100%;border:0;background:#007d96;color:white;border-radius:9px;padding:15px 18px;font-size:16px;font-weight:600;margin-top:22px}.calculate:hover{background:#00687e}.calculate span{font-size:23px}.error{padding:12px;border-radius:8px;background:#fff0e9;color:#994721;font-size:14px;line-height:1.5}.examples{margin-top:30px;border-top:1px solid #e3ebef;padding-top:15px}.examples p{font-size:13px;color:#66818d}.examples button{display:block;width:100%;text-align:left;background:transparent;border:0;border-radius:8px;padding:12px 8px;font-size:14px;color:#254955}.examples button:hover{background:#f1f7fa}.examples span{display:block;font-size:12px;color:#6c838d;margin-top:5px}.results .section-title{flex-wrap:wrap}.phase{margin-left:auto;font-size:12px;font-weight:600;color:#007589;background:#e5f4f5;border-radius:5px;padding:7px 10px}.properties{display:grid;grid-template-columns:repeat(3,1fr);gap:26px 12px}.property{padding:0 10px 15px;border-bottom:1px solid #e8eef1}.property .prop-head{font-size:13px;color:#617e8a;margin-bottom:10px}.symbol{font-family:Georgia,serif;font-style:italic;font-size:20px;color:#00879d;margin-right:8px}.value{font-size:29px;font-weight:500;letter-spacing:-.6px;white-space:nowrap;font-variant-numeric:tabular-nums}.unit{font-size:12px;color:#778e98;margin-top:7px}.result-bottom{display:flex;align-items:center;justify-content:space-between;gap:15px;margin-top:20px}.result-bottom p{font-size:12px;line-height:1.5;color:#6a818b;margin:0}.copy{padding:9px 12px;color:#327185;border:1px solid #cce0e6;border-radius:6px;background:white;font-size:12px;white-space:nowrap}.diagram{padding-bottom:18px}.diagram .section-title{margin-bottom:3px}.muted{margin-left:auto;font-size:12px;color:#728893}.diagram svg{display:block;width:100%;height:auto}.legend{display:flex;gap:22px;justify-content:center;font-size:12px;color:#68818a}.legend span{display:flex;align-items:center;gap:7px}.legend i{width:18px;height:2px;background:#25a1b5}.legend i.point{width:8px;height:8px;border-radius:50%;background:#ec7a3a}.explanation{grid-column:1 / -1;display:grid;grid-template-columns:1fr 2fr;gap:12px 40px;background:#e6f0f4;border-color:#d4e4ea}.explanation .eyebrow{grid-column:1;grid-row:1}.explanation h2{grid-column:1;grid-row:2;font-size:25px}.explanation>p:not(.eyebrow){margin:0;font-size:14px;line-height:1.7}.explanation #explain{grid-column:2;grid-row:1 / span 2}.formula{grid-column:1;font:italic 19px Georgia,serif;color:#007589}.explanation .hint{grid-column:2}.method{margin-top:24px;padding:18px 0;border-bottom:1px solid #d5e1e6;font-size:14px;color:#5b7380}.method summary{cursor:pointer}.method p{line-height:1.7;max-width:1000px}footer{max-width:1280px;margin:auto;padding:24px 42px;display:flex;justify-content:space-between;color:#7c939c;font-size:12px}button:focus-visible,select:focus-visible,summary:focus-visible,a:focus-visible{outline:2px solid #007d96;outline-offset:4px}[hidden]{display:none!important}.stale .value{opacity:.35}@media(min-width:1500px){main{padding-top:50px}}@media(max-width:950px){.workspace{grid-template-columns:310px 1fr}.panel{padding:20px}.value{font-size:24px}.properties{grid-template-columns:repeat(2,1fr)}.muted{display:none}.heading h1{font-size:36px}.intro{margin-right:0}.result-bottom{align-items:flex-start;flex-direction:column}}@media(max-width:700px){header{padding:18px 20px}.brand-sub,.standard{display:none}main{padding:26px 16px}.heading{margin-bottom:24px}.heading h1{font-size:33px}.intro{display:none}.workspace{grid-template-columns:1fr}.inputs{grid-row:auto}.properties{grid-template-columns:repeat(2,1fr)}.explanation{grid-column:auto;display:block}.explanation h2{margin:14px 0}.explanation>p,.formula{margin:14px 0!important}.value{font-size:29px}.result-bottom{flex-direction:row;align-items:center}.section-title{gap:9px}h2{font-size:16px}footer{padding:15px 20px;gap:14px;flex-direction:column}.phase{font-size:11px}.diagram{padding:16px 10px}}

.chart-switch{display:flex;margin-left:auto;padding:3px;background:#edf4f7;border-radius:7px;gap:2px}.chart-switch button{border:0;border-radius:5px;padding:7px 12px;background:transparent;color:#5e7a86;font-size:14px}.chart-switch button[aria-pressed="true"]{background:white;color:#007d96;box-shadow:0 1px 4px #15394418}.diagram .section-title{flex-wrap:wrap}.copy:disabled{opacity:.45;cursor:default}

#endpoints{margin-top:24px;border-top:1px solid #deeaee;padding-top:18px}#endpoints h3{font-size:15px;font-weight:600;margin:0 0 6px}#endpoints p{font-size:12px;color:#637f8b;margin:0 0 14px}#endpoints table{border-collapse:collapse;width:100%;font-size:14px;font-variant-numeric:tabular-nums}#endpoints th,#endpoints td{text-align:right;padding:11px 7px;border-bottom:1px solid #e5edf1}#endpoints th:first-child{text-align:left}#endpoints thead th{font-size:13px;color:#4e7584;font-weight:500;background:#f3f8fa}#endpoints small{display:block;font-size:11px;font-weight:400;color:#748c96;margin-top:3px}#endpoints td span{font-family:Georgia,serif;font-style:italic;color:#388296}@media(max-width:420px){#endpoints td{font-size:12px;padding:10px 3px}#endpoints td span{display:block;margin-bottom:4px}}

.feedback{margin-top:24px}.feedback form{max-width:720px}.feedback label{margin-top:20px}.feedback select,.feedback textarea{width:100%;font:inherit;color:inherit;padding:12px;border:1px solid #c4d6de;border-radius:8px;background:#f8fbfc}.feedback textarea:focus{outline:2px solid #007d96;outline-offset:2px}.feedback .calculate{max-width:260px}.feedback button:disabled{opacity:.5;cursor:wait}#feedback-status{line-height:1.5;font-size:14px}

/* Phone layouts: readable controls, touch targets and long numeric values. */
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
.panel,.property{min-width:0}#feedback-status{overflow-wrap:anywhere}
@media(max-width:700px){
 header{padding-top:max(16px,env(safe-area-inset-top));padding-left:max(20px,env(safe-area-inset-left));padding-right:max(20px,env(safe-area-inset-right))}
 main{padding:20px 16px}.heading h1{font-size:28px}.heading{margin-bottom:18px}
 #pair,.input-row select,.feedback select,.feedback textarea{font-size:16px;min-height:44px}
 button,.copy,.chart-switch button{min-height:44px}.copy{white-space:normal}
 .properties{grid-template-columns:repeat(2,minmax(0,1fr));gap:20px 10px}
 .property{padding:0 2px 12px}.value{font-size:clamp(21px,6.3vw,29px);white-space:normal;overflow-wrap:anywhere}
 .result-bottom{flex-wrap:wrap}.result-bottom p{flex:1;min-width:140px}
 .chart-switch{margin-left:0}.diagram .section-title{gap:8px}
 .feedback .calculate{max-width:none}.feedback textarea{resize:vertical}
 footer{padding-bottom:max(20px,env(safe-area-inset-bottom))}
}

@media(pointer:coarse),(max-width:950px){.copy,.chart-switch button{min-height:44px}}